Personal electronic devices are used for many different functions, and are very popular. Examples of such devices include personal digital assistants, palmtop computers, cellular telephones, digital medial players, and so on. The functions of these devices are often combined into single, multi-purpose devices. Thus, there is a convergence of function in the marketplace with respect to the design of personal electronics. As a result, these devices may often perform several tasks at a time.
One task for which such devices are increasingly used is audio playback and video with audio playback. That is, audio and video files may be stored on the device, and played back for the user to watch, hear or both. The audio processing involved has become sophisticated to the point that pre-processing of audio signals regularly includes audio shaping and other audio effects and enhancements. Pre-processing may emphasize certain frequency content of a signal to achieve a desired effect. Furthermore, while the device is engaged in audio playback, another function for which the device is designed may be triggered, and which may also generate an audio signal. For example, while listening to an music file, the device may receive a wireless telephone call. To alert the user to the call, the device will cut off the music and play an audio alert, or try and play the audio alert over the music. However, if the music is playing and has been enhanced in a frequency band used by the alert, the user may not perceive the alert. There is, therefore a problem with playing priority audio signals when non-priority audio signals are also being played, especially when pre-processing is used to enhance certain frequency content of the non-priority signals.